Modeling data acquisition during electrochemical noise measurements for corrosion studies

Electrochemical noise measurement and analysis enable one to obtain information on corroding systems without applying any potential or current perturbation to the corroding surface, and they are thereby nondestructive techniques, suitable for corrosion monitoring. The measurement process requires converting the analog potential or current signal in a digital dataset that can be used to perform mathematical operations with a variety of approaches. The analog-to-digital conversion is a critical step since, after the conversion has been performed, it is impossible to correct for artefacts that occurred during the conversion. Additionally, the electrochemical noise generated during corrosion is generally overlapped to the instrumental noise and to the electrical interference that are present in the environment where the measurement is performed. In this work, the process of analog-to-digital conversion of electrochemical noise signals is analyzed in detail by simulating the conversion of a representative simulated noise signal. With this approach, the possible issues arising from the analog-to-digital conversion process are highlighted and the key features arising from instrumental noise, aliasing, and electrical interference are identified.